Usisipho Feleni
Usisipho Feleni obtained her BSc honours in chemistry from the University of the Western Cape (UWC) in 2012 and her MSc in nanoscience (with specialisation in nanochemistry) from UWC in 2014. She is now completing a PhD in chemistry (with specialisation in nano-biosensors) at the same university.
Feleni is fascinated by the inter-individual variability in drug metabolism (particularly for antiretroviral, anti-tuberculosis and breast cancer drugs) and how this is related to patients’ responses to treatment, drug toxicity and drug resistance. Her research project addresses a serious health need in South Africa: addressing the development of a cost-effective diagnostic system for early detection of diseases, enabling timely intervention and effective management.
Alongside HIV and Tuberculosis, breast cancer is regarded as a priority disease in South Africa’s health management system. Clinical oncologists and pharmacologists are trying to understand the effectiveness of tamoxifen — the most prescribed breast cancer drug — in cancer therapy. Genotype test protocols, such as Roche’s AmpliChip CYP450 test, can indicate poor, moderate and ultra-rapid metabolisers of tamoxifen, but they are extremely expensive, at $1 300 per test.
Feleni’s PhD project introduces the next-generation phenotype-based b-cancernanosens for sensing and signalling tamoxifen bioactivity and biotransformation. This is a low-cost, bipolar bioreactor-on-a-chip, comprising the biocompatible palladium telluride-quantum dots-modified genetically engineered cytochrome P450-2D6 and cytochrome P450-3A4 that, in preliminary tests, promise to be suitable for providing a patient’s complete response profile for tamoxifen at point-of-care (the doctor’s office).
A bioalert system such as the one Feleni is developing will be very sensitive (down to femtomolar concentrations) and suitable for signalling drug metabolic activity in real time (in a few seconds). This study will present an important application of nanomaterials in medical diagnostics, with the ultimate aim being to contribute to improving the quality of life for women, particularly breast cancer patients.
Feleni has published and contributed to nine journal articles and a book chapter in the area of therapeutic drug monitoring nano-biosensors. She was awarded a visiting junior researcher fellowship (under the Marie Curie European Union-FP7 SmartCancersens project) to perform research at the Biosensors and Bioelectronics Centre, Linköping University, Sweden, from August 2014 to March 2015. She was also awarded a Graduate Research and Creative Achievements Forum Fellowship that enabled her to participate in the Summer School of the Faculty of Medicine at the University of Missouri, US, from May to July 2015.